Enlarge / Thomas Homan, Acting Director of U.S. Immigration and Customs Enforcement, seen here during a February 2016 Senate hearing. (credit: Al Drago/CQ Roll Call/Getty Images News) The acting head of Immigration and Customs Enforcement (ICE), the federal agency charged with deportations, has confirmed in a new letter that it does not use cell-site simulators, also known as stingrays, to locate undocumented immigrants. In the August 16 letter, which was sent to Sen.